US2989969A

US2989969A - Method and arrangement for preventing the risk of reaction between reactive fluids

Info

Publication number: US2989969A
Authority: US
Inventors: Gascoin Jorge Enrique Ernesto
Original assignee: ADELINA STRADA
Current assignee: ADELINA STRADA
Priority date: 1959-03-16
Filing date: 1959-03-16
Publication date: 1961-06-27
Anticipated expiration: 1978-06-27

Description

June 27, 1961 J. E. L. E. GASCOIN 2,989,969

METHOD AND ARRANGEMENT FOR PREVENTING THE RISK OF REACTION BETWEEN REACTIVE FLUIDS Filed March 16, 1959 ww w mlw m- INVENTOR, 49. 1.15 W BY AMA A1 United States PatentO 2,989,969 METHOD AND ARRANGEMENT FOR PREVENT.

ING THE RISK OF REA'CI'ION BETWEEN RE- ACTIVE FLUIDS Jorge Enrique Luis Ernesto Gascoin, 3155 Acevedo St., Bnenos Aires, Argentina, assignor of one-half to Adelina Strada, Buenos Aires, Argentina Filed Mar. 16, 1959, Ser. No. 799,736 12 Claims. (Cl. 137-1) This invention relates to a method as well as to an arrangement for preventing the risk of reaction between reactive fluids during transfer of one fluid from a first container to a second container, as well as to the storing and/or transferring of a combustible, usually inflammable fluid, which in most of the cases is a liquid, in an explosion and'fire safe Way.

More particularly the present invention refers to a process and equipment which enables the handling and storing of inflammable liquids in such a way that the vapors which are evaporated from the liquid as well as the liquid itself cannot enter in contact, with the air or a gas containing free oxygen which would permit a combustion or explosion to take place. Itwill be appreciated that the invention may be used many different circumstances, such as for instance when transferring hydrocarbon compounds, such as fuel, from one container to another, where nowadays, in the presence of any kind of spark or flame the entire equipment may explode or be set on fire.

For the purpose of this specification and the appendant claims, it will be apparent to those skilled in the art, that theterm fluid tends to cover both liquids as well as gases and more particularly for this specification those gaseous compositions which contain a lighter evaporable component which may have the tendency to explode or be. set on fire.

.Since in most of the cases the fluid is a liquid, the term liquid will now be usually employed in describing the invention, although it is to be understood that this term does not exclude the possibility of replacing the liquid by a suitable gas as above explained.

The term combustible defines for the purpose of this specification and the appendant claims those products which may explode with or without fire and not necessarily require as a comburent, oxygen.

.2 Since the invention is preferably, although not exclusively applied to liquid hydrocarbons the term. inflammable will usually be used; however such a term does not tend to limit the inventive concept in view of the above explanation as to the term combustible. Therefore, when reading the specification, anyone skilledin the art, by parallelism will have to interpret the term inflammable as likewise covering those explosions where there is no flame. -11 Itjis Well known that for filling or emptying 'a tank containing a liquid, it is necessary to allow the air stored in that tank to be discharged to atmosphere in the first case, and to suction in air from the atmosphere in the second case. When the liquid is a non-inflammable one, such as for instance water, the operation may be carried out-without any danger, but when said liquid is an evaporable and inflammable one, due to the presence of oxygen or another comburent, in case of another combustible liquid, any spark or flame or the like which may there'be produced, for instance by accident, will provoke a disaster.

- When such a combustible liquid contained in a tank is to be transferred, a considerable proportion is lost imme diately, more particularly that portion which was previously evaporated in the tank. It must be added that such an evaporation and loss even takes place in a storage Patented June 27, 1961 tank during storage, particularly if the environment temperature is subject to more or less important changes such as from day to night time, due to the phenomena known as respiration.

It is, therefore, a purpose and object of the present invention to avoid those drawbacks, such as by providing a method as well as an arrangement which permit the transfer of such a liquid or fluid from one container to another without any danger as to an explosion or fire, at the same time as those portions of the combustible liquid or fluid which have been evaporated may be condensed and thus recuperated without requiring costly modifications of existing installations.

The present invention may be applied to any type of container, that is to say not only storage tanks but likewise vessels, trucks and airplanes, particularly during refueling of aircraft.

The present invention is based on the fact that in the container housing the combustible fluid, such as an inflammable liquid, which defines a level within said tank, a first heavy inert gas is located on said level and thereabove a second inert gas lighter than said first inert gas and also lighter than the vapours which may evaporate from said liquid, thus defining in the container a lower liquid zone, an intermediate heavy blanket gaseous zone and an upper gaseous zone. The vapours which are evaporated by said combustible liquid may filter through the heavy blanket gaseous zone inasmuch asthe density of said first gases is larger than the density of said vapours. These vapours will be trapped between said first and second inert gases due to the fact that the density of said second inert gas is lower than the density of said vapours. The upper gaseous zone is connected to a controllable supply source of said second gas, so that when said liquid is to be transferred, additional gas maybe supplied or vice-versa, when liquid is to be stored excessive gas may be withdrawn from said container by said controllable supply source.

In order to recuperate the vapours which may be within said second gas it is suflicient to pass said mixture through any type of condenser or dephlegmator, to condense and separate as a liquid, those vapours which are then recuperated. V

Amongst those inert gases herein before defined as the first inert gas particularly when the liquid to be stored is a hydrocarbon, heavy fluorinated hydrocarbons may be used. The term heavy" is to be interpreted as defining such a first inert gas which is heavier than the vapours which the liquid hydrocarbon may evaporate.

' As to the second inert gas herein before defined nitrogen, carbon dioxide and the like may be used.

In order to facilitate the comprehension of the structural part of the invention, reference will now be made, by way of example, to several preferred embodiments shown in the accompanying drawings, wherein:

FIGURE 1 is a schematical longitudinal section of a first arrangement, showing the transfer of a liquid from a first tank into a second tank defining a so called closed circuit.

FIGURE 2 is a somewhat schematical longitudinal section of a second arrangement, wherein the transfer of a liquid from a first container to an open tank, such as used in airplanes, motor cars and the like, is shown.

FIGURE 3 is likewise a schematical longitudinal section of a container, wherein the liquid is storaged and said container being connected to a condenser and pressure control supply source of the second inert gas, said pressure control supply source being likewise a dephlegmato-r for separating the condensate of the evaporated liquid.

FIGURE 4 is a longitudinal section of an automatic closure member.

As may be appreciated from FIG. 1 the closed circuit arrangement consists of a first tank 1 containing a hydrocarbon liquid 2 which is of course a combustible as well as an inflammable liquid which in the first instance is stored in said first container 1 and in the second instance has to be transferred to a second container 3.

The first container 1 comprises a bottom portion 4 having a discharge outlet 5 controlled by a throttle valve 6 having a discharge pipe 7. The first container further comprises a top portion 8 having a similar arrangement as the bottom portion 4, that is to say an inlet 9 and a throttle valve 10 connected thereto having an inlet pipe 11.

Within said first container 1 the hydrocarbon liquid 2 is stored defining a level L on which a first heavy inert gas 12 is located which defines an intermediate heavy blanket gaseous zone. The term heavy has already been previously explained. Above said blanket zone 12 a second inert gas 13 is arranged which fills out the remainder of said first container 1 and which second inert gas is lighter than said first inert gas.

Examples as to the type of inert gases which may be used, have already been described above;

It is, of course, assumed that the

throttle valves

6 and 10 are closed. If the liquid 2 is to be transferred to a second container 3 Without entering into contact with air, supposing that the liquid is a hydrocarbon, to avoid risks as to explosions and/or fire, the discharge pipe 7 is connected to a first conduit 14, which is usually a flexible hose for facilitating handling, and the inlet pipe 11 is connected to a second conduit which is likewise usually a flexible hose. The ends of both conduits 14 and 15 are each provided with an automatic closure member 16, 16a, 16b and 160 respectively, which assure that the fluids contained in said conduits 14 and 15 do not enable the entry of air into said conduits.

These automatic closure members are already well known in the art and for illustrative purposes one is shown in FIG. 4 and consists of a housing 17 made of two halves 17' and 17" riveted together by rivets 18 with a sealing disk 19 in between them, which disk is provided with a ring of spaced apart passage openings 20 and a central opening 21, guiding a valve stem 22 having a valve head 23 spring urged by spring 24 towards a valve seat 25 defined in the housing 17 and more particularly in half 17". This half 17" ends in an inlet ring 26 into which the discharge pipe 7 may be fit, which discharge pipe 7 is integral with a radial shoulder 27 and loosely supponts a connecting nut 28. Within the front end of the discharge pipe 7 a three legged spider 29 is rigidly arranged (only one leg being visible) and supporting a valve head operating projecting member 30 projecting out of said front end of said discharge pipe. A gasket 31 is usually mounted on the front end of said radial shoulder 27. The inlet ring 26 is screw threaded on its periphery.

It will be understood by those skilled in the ant that when the discharge pipe 7 is fit into the inlet ring 26 by connecting nut 28 to the inlet ring 26, that the valve head operating projecting member 30 will gradually open the valve by pushing the valve head 23 into the position shown in FIG. 4, thereby connecting the first container .1 to the second container 3 provided that the throttle valve '6 and a similar throttle valve 6 integral with an inlet pipe 32 which ends near the bottom 33 of the second container 3 are opened (see FIG. 1).

The first conduit 14 contains in this particular instance the same hydrocarbon liquid as that contained by the first container 1. i

The top portion 34 of the second container 3 and which supports the inlet pipe 32, is further provided with an outlet pipe 35 having a throttle valve 10'.

The second conduit 15 is connected in a similar way as the first conduit 14 as is apparent from FIG. 1. The

second container 3 to be filled contains the same heavy inert gas 12 and the same second inert gas 13. When the transfer is started, by opening the four

throttle valves

6, 6, 10 and 10, the liquid 2 will be transferred from the first container 1 through the first conduit 14 and inlet pipe 32 near the bottom 33'into' the second container 3, whereby the heavy inert gas 12 of the second container is gradually raised and the lighter second inert gas 13 of the second container is gradually transferred through the second conduit 15 into the first container 1. As soon as the total transfer or the desired amount of liquid to be transferred is accomplished, the four

throttle valves

6, 6, 10 and 10 are closed and the first and second conduits 14 and 15 may then be Withdrawn.

The second container 3 may for instance be the tank of a truck or another movable unit to be transported.

Instead of using a closed circuit, as above described, in many circumstances an open circuit has to be used such as for instance at a filling station, where fuel has to be supplied to customers, for instance motor cars. The tank of the motor car is identified in FIG. 2 by reference numeral 36 having a fuel inlet 37 and an air outlet 38. In this embodiment the container 39 which is the equivalent of container 1 in the embodiment described in connection with FIG. 1 again contains a liquid 2, a first heavy inert gas 12 and a second inert gas 13. The top portion 40 of tank 39 is likewise provided with a controllable throttle valve 10 connected to a supply source 41 of said second inert gas. This supply source 41 may for instance be a bottle containing said second gas in highly compressed and liquid state. Said supply source 41 is connected to said throttle valve 10 through a distention device 42 and a pressure control valve 43. The bottom portion 44 is provided with a discharge pipe 45 connected to a pump device 46.

If a tank 36 has to be refilled, such as shown in FIG. 2, pump 46 is operated, whereby liquid 2 is withdrawn from container 39 and accordingly the pressure within said container 39 decreases so that the pressure control valve 43 will be opened and thereby the distention device 42 enables the passage of additional gas supplied by the supply source 41. The distention device 42 is a device which transforms the liquid supplied by the supply source 41 into gas, as is well known by those skilled in the art.

It may likewise be conceived that the container 39 of FIG. 2 is the equivalent of container 3 of FIG. 1, in which event said container 3 only requires at its bottom portion an outlet to be able to be connected to the discharge pipe 45, shown in FIG. 2.

In the embodiment of FIG. 3, the container 101 which is the equivalent of container 1 in FIG. 1, is likewise provided with

throttle valves

6 and 10, a discharge pipe 7 and an inlet pipe 11. The top portion 108 of container 101 is in addition provided with a pressure 00mpensating pipe 47 connected to a condenser 48 and ending into a pressure control supply source or dephlegmator 49. Container 101 contains, similarly as container 1, the liquid 2, the first heavy inent gas 12 and the second inent gas 13. The heavy inert gas 12 defines a heavy blanket gaseous zone through which vapours which are evaporated by the liquid 2 and which are schematically indicated by a layer of bubbles 50, may filter. Since the second inert gas is lighter than the layer of bubbles or vapours, these will rest in a large proportion on the first heavy inert gas or blanket 12 which of course is heavier than said vapours 50. However, part of those vapours particularly when large expansions take place, such as during a hot day, will leave together with the second gas 13, container 101, through pressure compensating pipe 47 and are condensed then by condenser 48, to be finally discharged together with the second gas into the pressure control supply source 49 which is of the type of a gasometer, where the second inert gas will rise the dome like chamber member 51 whilst the condensate 52 which is again in liquid state will be stored in the bottom portion of the pressure control supply source 49. "A discharge cock 53 enables to recuperate said condensate 52. If the fluid in container 101 contracts, such as during a cold night, the dome like chamber member 51 will press the second inert gas stored therein back into the container 101. 1

It will be evident to those skilled in the art that for specific purposes the present invention may be modified within normal skill, such as for instance in some cases it may be, advisable that the storage container is suitably protected so as to become bullet proof; for instance it could be conceived that a second tank surrounds the storage container, which second tank contains a suitable inert gas. Since this example does not form as such part of the inventive concept, it is not considered necessary to illustrate specific examples thereabout.

I claim:

1. An explosion and fire safe method for handling a combustible liquid, comprising the steps of partially filling a container with said liquid, so as to define in said container a level and locating on said level a first heavy inert gas and thereabove a second inert gas lighter than said first inert gas and lighter than the vapours which may separate from said liquid to thereby define a lower liquid zone, an intermediate heavy blanket gaseous zone and an upper gaseous zone, and maintaining said upper gaseous zone in communication with a supply source of said second gas, said heavy, inert gas being heavier than the vapors which normally separate from said liquid, the difference in densities between the heavy inert gas, the light inert gas, and the vapors which separate from the liquid, is such that they will form substantially distinct layers above the liquid.

2. A method as recited in claim 1 wherein the vapors which separate from said liquid and filter through said heavy blanket gaseous zone are condensed between said supply source and said container.

3. A method as recited in claim 1 wherein the liquid is discharged into a second container through a discharge opening in the first container below said level.

4. A method as recited in claim 3 wherein said second container is provided during transfer of said liquid with a heavy blanket gaseous zone and a layer thereabove of said second inert gas.

5. An arrangement for fire and explosive proof handling of a combustible liquid comprising a container having a top portion and a bottom portion, controllable liquid discharge means connected to said bottom portion, said combustible liquid being housed in said container and defining therein a level, a heavy inert gas located on said level defining an intermediate blanket zone and a second inert gas lighter than said first inert gas and lighter than the vapors which may separate from said liquid arranged on said intermediate blanket zone, inlet means in said top portion and a supply source of said second gas connected to said inlet means, said heavy, inert gas being heavier than the vapors normally separating from said liquid, the difierence in densities between the heavy inert gas, the light inert gas, and the vapors which separate from the liquid, is such that they will form substantially distinct layers above the liquid.

6. An arrangement as recited in claim 5 including a second container, conduit means providing communication between said liquid discharge means and the interior of said second container, said supply source of said second gas being said second container.

7. A closed circuit arrangement for storing and transferring in a fire and explosive proof way in inflammable liquid in a first container to be transferred into a second container, said first container having a top portion and a bottom portion, each of said top and bottom portions being respectively provided with first and second controllable throttle valve means, said inflammable liquid being housed in said first container defining therein a level, a first heavy inert gas located on said level and defining an intermediate heavy blanket gaseous zone, a second inert gaslocated on said blanket zone and being lighter than said first inert gas and lighter than the vapors, which may separate from said inflammable liquid and filter through said blanket zone, said second container having a top portion and a bottom portion, said top portion supporting an inlet pipe ending in said tank near said bottom portion, a third controllable throttle valve means connected to said inlet pipe, a fourth controllable throttle valve connected to said second container, said second container having at least a heavy blanket gaseous zone and an upper gaseous zone, said second throttle valve means being connected to said third throttle valve means and said fourth throttle valve means being connected to said first throttle valve means so that upon opening all said throttle valve means said inflammable liquid may be transferred from said first container into said second container and at least part of said second insert gas of said second container may be transferred into said first container, said heavy, inert gas being heavier than the vapors which normally separate from said liquid, the difierence in densities between the heavy inert gas, the light inert gas, and the vapors which separate from the liquid, is such that the will form substantially distinct layers above the liquid.

8. A closed circuit arrangement as claimed in claim 7, wherein a first conduit containing said inflammable liquid is connected between said second and third throttle valve means and a second conduit containing said second inert gas is connected between said fourth and first throttle valve means.

9. An open circuit arrangement for storing and transferring in a fire and explosive proof way an inflammable liquid from a first container into an atmosphere opened second container, wherein said first container comprises a bottom portion and a top portion, said inflammable liquid being housed in said first container and defining a level therein, a first heavy inert gas arranged on said level and thereabove a second inert gas lighter than said first inert gas and lighter than the vapors which may separate from said liquid, a supply source of said second gas connected to said top portion, and discharge means connected to said bottom portion for discharging said inflammable liquid into said second container, said heavy, inert gas being heavier than the vapors normally separating from said liquid, the difference in densities between the heavy inert gas, the light inert gas, and the vapors which separate from the liquid, is such that they will form substantially distinct layers above the liquid.

10. An open circuit arrangement as claimed in claim 9, wherein pressure control means are arranged between said supply source and said top portion of said container.

11. An arrangement for storing fire and explosive proof an inflammable liquid and for recuperating vapors from said inflammable liquid, which vapors may have evaporated during storage, comprising a container having a top portion, said inflammable liquid being housed in said container and defining a level therein, a first heavy inert gas on said level and thereabove a second inert gas lighter than that first inert gas and lighter than the vapors, which may separate from said liquid and filter through said first heavy inert gas, a pressure compensating pipe connected to said top portion, a condenser forming part of said pressure compensating pipe, at pressure control supply source in form of a gasometer, said pressure compensating pipe ending into said pressure control supply source adapted to discharge therein the condensate condensed by said condenser and said second inert gas, and discharge means for discharging said condensate from said pressure control supply source, said heavy, inert gas being heavier than the vapors normally separating from said liquid, the difierence in densities between the heavy inert gas, the light inert gas, and the vapors which separate from the liquid, is such that they will form substantially distinct layers above the liquid.

12. An explosion and fire safe method for handling 7 a combustible liquid comprising the steps of partially filling a container with said liquid so as to define in said container a level, locating on said 'lev ela first heavy, inert gas, said gas'being heavier than the vapors normally separating from said liquid, locating thereover a 5 second inert gas lighter than saidfirst inert was and lighter than the vapors which normally separate from said liquid to thereby define in said container a lower liquid zone, 1,406,479 an intermediate heavy blanket gaseous zone and an up- 1,533,587 per gaseous zone, the difierence in densities between the 10 2,854,826

heavy inert gas, the light inert gas, and the vapors which separate from the liquid,. is Such that they will form substantially distinct layers above the liquid.

References Cited in the file of patent UNITED STATES PATENTS Muchka Feb. 14, 1922 'Durborow Apr. 14, 1925 Johnston Oct. 7, 1958 arr "t